docs: def create_search_index(self, index, schema=None, n_val=None,
                              timeout=None):
          """
          Create a Solr search index for Yokozuna.
  
          :param index: a name of a yz index
          :type index: string
          :param schema: XML of Solr schema
          :type schema: string
          :param n_val: N value of the write
          :type n_val: int
          :param timeout: optional timeout (in ms)
          :type timeout: integer, None
  
          :rtype boolean
          """
          if not self.yz_wm_index:
              raise NotImplementedError("Search 2.0 administration is not "
                                        "supported for this version")
  
          url = self.search_index_path(index)
          headers = {'Content-Type': 'application/json'}
          content_dict = dict()
          if schema:
              content_dict['schema'] = schema
          if n_val:
              content_dict['n_val'] = n_val
          if timeout:
              content_dict['timeout'] = timeout
          content = json.dumps(content_dict)
  
          # Run the request...
          status, _, _ = self._request('PUT', url, headers, content)
  
          if status != 204:
              raise RiakError('Error setting Search 2.0 index.')
          return True